Feed through insulator



I. M. MILLER July 4, 1967 FEED THROUGH I NSULATOR Filed Jan. 21, 1966 FIG. 1

m m u INVENTOR IMRICH M. MILLER ATTORNEYS V United States Patent 3,329,762 FEED THROUGH INSULATOR Imrich M. Miller, Paterson, N.J., assiguor to Universal Manufacturing Corporation, Paterson, N.J., a corporation of New Jersey Filed Jan. 21, 1966, Ser. No. 522,295 6 Claims. (Cl. 174-65) This invention relates to insulators and more particularly to insulator members for feeding electric current carrying wires through the housing of an electrical device.

Many electrical devices have the need for one or more insulator members for feeding current carrying wires, either insulated or uninsulated, through the housing of the device for connection to another component or current supply source. The present invention is directed to so-called feed-through insulator members of this type, these members being economical to make, readily mountable on the housing of the device and permitting easy passage of the wires therethrough during assembly of the device.

In accordance with the invention, insulator members are provided wth one or more apertures formed therein through which the current carrying wires are to pass from the inside to the outside of a housing of an electical component or device. A slit or cut, is made in the member from the aperture to one of its edges so that the membercan be bent along this cut to provide access to the aperture. This permits the wires to be laid in the aperture through the slit, rather than threaded through the aperture in the conventional manner. This results in a saving of assembly time.

In a preferred embodiment of the invention, the housing on which the insulator member is used is provided with a cut-out portion which communicates with the cut on the member. This permits the wires to be placed in the aperture of an insulator member after the member has been placed in the housing, or alternatively, to permit direct mounting of an insulator member with wires already passing therethrough to the housing.

Additional features of the invention include the provision of a second cut in the member, in addition to the access cut, to make the bending of the member easier and to increase access of the wires to the aperture. An arrangement is also provided in the form of an arm or an insulator member engaging one or more insulator holding members on the housing, for mounting the member to the housing. Further the member is provided with arms extending in several directions to stabilize it in the housing.

It is therefore an object of the present invention to provide feed-through insulators which are simple and economical to construct and to assemble to an electrical device.

Another object is to provide a feed-through insulator in which access to the aperture through which the wires pass is provided from an edge of the insulator.

An additional object is to provide a feed-through insulator member with one portion for mounting the member in a housing and a second portion for providing stability, the member having at least one aperture therein to which access is had from an edge of the member.

Yet another object is to provide a feed-through insulator in combination with a housing in which access to the aperture of the insulator member is available directly through an open portion of the housing.

Other objects and advantages of the present invention will become more apparent upon reference to the following specification and annexed drawings in which:

FIGURE 1 is a bottom view of an electrical transformer device utilizing the present invention;

3,329,762 Patented July 4, 1967 FIGURE 2 is a perspective view of a portion of one end of the housing of FIGURE 1 showing one embodiment of insulator member;

FIGURE 3 is an end view of the housing of FIG- URE 1;

FIGURE 4 is a sectional view of the end of the housing taken along lines 4-4 of FIGURE 3; and

FIGURES 5 and 6 are elevational views of one end of a housing of an electrical device taken from opposite sides thereof showing another embodiment of the invention.

Referring first to FIGURES 1-4, one embodiment of insulator member 10 of the present invention is shown used at each end of a metal housing 25 of a fluorescent light ballast transformer. Of course, the insulator can be used with any type of electrical device. The ballast includes a transformer 27 having primary and secondary windings 28 and 29 mounted on a core or yoke 30. Transformer 27 has the usual insulated terminal boards 31 and 32 mounted thereon, each with a number of upstanding contacts 34 to which one or more insulated wires 36 are connected. Wires 36 pass outside of each end of the housing 25 for connection either to a power supply source or to the leads and/ or sockets of one or more fluorescent lamps. A starting capacitor 38 and a running capacitor 39 are also connected to various contacts 34 on the terminal boards while a resistor 40 is connected across two of the terminals of capacitor 39. The particular connections of the wires, resistors and capacitors form no part of the present invention and are described merely to place the invention in a suitable environment.

In assembling an electrical transformer device of the type shown in FIGS. 1-4, a potting compound of an asphaltic or asphaltic-plastic, or any suitable type of composition, is poured over all of the components after they are fully assembled. This potting compound is not shown here.

As should be evident, it is necessary to bring the wires 36 from the transformer 27 and other portions of the device from the inside to the outside of housing 25. This must be done so that the insulation is not rubbed off wires 36 or, if uninsulated wires are used, to prevent them from shorting to the housing. To do this, an insulator member 10 is used at each end of the housing. Of course, if desired, an insulator member can be placed at only one end of the housing or else may be located at any portion of the housing in a desired manner.

As shown best in FIGS. 2-4, the insulator member 10 is generally T-shaped and has a cross-arm 11 and a downwardly extending arm 12. As illustratively shown, a pair of oval apertures 14 are formed in cross-arm 11. However, as many apertures as needed can be used. A cut or slit 16 extends from the upper, inner portion of each aperture 14 to the top edge of the cross-arm. Another slit 17 is cut in arm 11 from each aperture 14 and extends in a generally opposite direction from the other aperture slit 16. Each cut 16 permits the member 10 to be bent therealong to provide access to its corresponding aperture 14. The second cut 17 further enhances the bending. Where two apertures 14 and two sets of slits 16-17 are used, a bendable tab 18 is formed therebetween on the member 10.

The insulator member 10 is made of any suitable material, such as paper or cardboard, plastic, nylon, etc. The exact material will, of course, depend upon the particular use to which the insulator member is to be made including the breakdown voltage it is to carry, rubbing requirements for the wires, etc. Where paper, cardboard or other similar material is used, the insulators 10 are stamped out by a simple die in the proper shape together with apertures 14 and slits 16 and 17. This, of course, is

:3 very economical as compared with conventional molded plastic insulators.

The insulator member is mounted on the end wall 26 of the housing 25 by a pair of upwardly extending fingers or hooks 42 punched out of the end wall and bent in the desired shape. The fingers 42 engage member 10 at the junction of the arms 11 and 12 but, of course, they can engage any part of the cross-arm. An opening 44 is also cut in each end wall. Opening 44 exposes at least the apertures 14 and its top is partially closed by two arms 47 over the cuts 16 to prevent the tab portion 18 of the member 10 from being bent outwardly of the housing and wall 26. However, access is provided to both slits 16 through the space 49 between the two arms. A portion 48 of the housing end wall engages the center of the crossarm 11 of the insulator 10 whose periphery is framed by the end wall so that it cannot be pulled out of the housing through opening 44. The downwardly extending arm 12 provides lateral stability for the member 10 to prevent its being moved transverse to the housing end wall.

Where the insulator 10 is used with a housing 26 having a mounting flange 50 thereon, the flange 50 is also provided with an opening 52 which extends completely thereacross and communicates with the access opening 49 to the slits 16.

The assembly of the insulator member and the placing of the wires therein is done in a relatively simple manner. As illustrated best in FIGS. 2 and 3, the member 10 is mounted in the fingers 42 at each end of the housing. The tab 18 formed by the pairs of cuts 16 and 17 is bent back and one or more wires is passed through the access openings 52 and 49 into a slit 16 and placed into one of the apertures 14. With the tab 18 still held back one or more wires is placed into the other aperture 14 through the communicating slit 16. After all of the wires are laid in their respective apertures, the tab 18 is pushed back against the arms 47 and the wires 36 are now locked in the proper position. It should be clear that the foregoing assembly is accomplished in a quick and easy manner since it is not necessary to thread any of the wires through an aperture 14. It is only necessary to lay them in the apertures 14 through a slit 16 after the tab 18 has been bent back and this is readily done since there is access to the slits from the top of an end wall through openings.

FIGURES and 6 show another embodiment of the invention in which the insulator 60 is of slightly dilferenent construction than the insulator of FIGS. 14. Here, the cross-arm 61 is formed with an upper portion 62 and a lower portion 63 of somewhat smaller width. The end wall 26 of the housing has a pair of arms 74 bent inwardly toward each other to engage cross-arm portion 63 at its junction with portion 62. The same arrangement of the apertures and slits 14, 16 and 17 as in FIG. 1 is provided here. Also, depending from the cross-arm is a long arm 65 with an extending portion 66 on its lower extremity. This again is to provide stability for the member 67. The assembly of wires into this insulator member is accomplished in the same manner as previously described. While preferred embodiments of the invention have been described above, it will be understood that these are illustrative only, and the invention is limited solely by the appended claims.

What I claim is:

1. In combination with a housing,'a wire feed-through insulator formed with a pair of apertures through which wires are adapted to pass, said member also formed with a pair of cuts from a first edge thereof one to each of said apertures to form a bendable tab between said two outs to provide access for the wires to said apertures, said housing formed with an opening in a wall through an edge thereof, and means on said housing for holding said member to permit wires to be inserted in said cuts from said edge of said housing.

2. An insulator member as in claim 1 wherein the member is formed with a second cut extending from each aperture in a generally transverse direction from the first edge of the member and forms a continuation of the firstnamed cut of each aperture.

3. An insulator member as in claim 1 wherein said member is generally T-shaped with a cross-arm and an arm depending downwardly therefrom with said apertures and said first-named cuts being formed in the cross-arm.

4. The combination of claim 3 wherein said means on the housing for holding the feed-through insulator Inember engages the cross-arm thereof and said downwardly extending arm engages said wall.

5. The combination of a sheet metal housing having an opening in a wall thereof, a wire feed-through insulator member, said member formed with an aperture through which one or more wires are adapted to pass from one side of said wall to the other and a cut extending from an edge of the member to said aperture and means for holding said member to said housing with the aperture in registry with said wall opening and with said member having a portion bendable about said cut to permit a wire to be inserted through said cut into said aperture and through said opening from outside the first edge of the member.

6. The combination of a sheet metal housing having an opening in a wall thereof which extends to the edge, a wire feed-through insulator member, said member formed with a pair of apertures through which one or more wires are adapted to pass from inside to outside of the housing and a cut extending from a first edge of the member to each of said apertures forming a bendable tab portion therebetween, said cuts being accessible through said wall opening whereby wires can be inserted into said apertures through said wall opening from the said first edge of the member, and means for holding said member to said housing with the apertures thereof in registry with the wall opening.

References Cited UNITED STATES PATENTS 2,032,832 3/1936 Blair et al. -90.6 2,148,449 2/1939 Edwards 174152 X 2,382,970 8/ 1945 Brocherdt. 2,517,717 8/1950 Rose. 2,846,246 8/ 1958 Peras. 3,188,592 6/1965 Kukla. 3,229,026 1/1966 Sulzer 17465 LARAMIE E. ASKIN, Primary Examiner, 

5. THE COMBINATION OF A SHEET METAL HOUSING HAVING AN OPENING IN A WALL THEREOF, A WIRE FEED-THROUGH INSULATOR MEMBER, SAID MEMBER FORMED WITH AN APERTURE THROUGH WHICH ONE OR MORE WIRES ARE ADAPTED TO PASS FROM ONE SIDE OF SAID WALL TO THE OTHER AND A CUT EXTENDING FROM AN EDGE OF THE MEMBER TO SAID APERTURE AND MEANS FOR HOLDING SAID MEMBER TO SAID HOUSING WITH THE APERTURE IN REGISTRY WITH SAID WALL OPENING AND WITH SAID MEMBER HAVING A PORTION BENDABLE ABOUT SAID CUT TO PERMIT A WIRE TO BE INSERTED THROUGH SAID CUT INTO SAID APERTURE AND THROUGH SAID OPENING FROM OUTSIDE THE FIRST EDGE OF THE MEMBER. 